1. Field of the Invention
The present invention relates to a method for inspecting or testing objects, particularly for detecting defects or irregularities therein, wherein the object to be inspected is moved in a rotary manner in an X-ray using a manipulating system, and the X-ray components, comprising X-ray tubes and X-ray detectors, are moved in a translatory manner, as well as to an apparatus for performing the method according to the invention.
2. Description of the Related Art
EP 984 301 A1 teaches a method for the inspection of luggage. The introduction to the aforementioned specification refers to fundamentally different possibilities for completely scanning an item of luggage.
Modern testing and inspecting systems for the detection of defects in castings and the like using X-rays operate according to two different principles, and the inspection object is either moved in the X-ray or the X-ray chain, comprising tube and detector, is moved around the object. In the first solution, the X-ray components are installed in a fixed manner, with the inspection object normally being grasped by a robot and moved into the x-ray beam. This makes it possible to inspect all positions of a part. In the second solution, the inspection object is stationary on a conveyor system, e.g. a pallet, and the X-ray components fixed to a C-arm or O-arc are moved around the inspection object.
In the first solution, the gripper gives rise to problems because in at least one position it is in the image and also the positioning precision is limited by wear and part tolerances. In addition, the costs of the robots are high compared with the overall installation.
In the second solution a very strong and therefore heavy, voluminous mechanism is required in order to bring the X-ray components into position in the short time available. In addition, the strong accelerations give rise to vibrations, which introduce blurring in the image and limit the inspection precision.
Therefore the problem of the invention is to improve the aforementioned method in such a way that it not only detects or recognizes smaller defects, but at the same time brings about a shorter inspection time with a very small physical size. The latter means that the mechanism must operate faster and with higher precision.
According to the invention, this problem is surprisingly solved in that the X-ray components are only moved in translatory manner and the test object or part is only moved in rotary manner in a cardan or gimbal suspension. In other words, the movement is divided up into a rotary inspection object movement and a translatory X-ray component movement. As a result, the necessary movements are minimized and, in particular, the rotation of larger masses far away from the center of gravity is prevented by the use of gimbal suspensions. The invention ensures that an inspection object can be moved in a translatory manner in the x-ray beam in one plane over the entire inspection object dimensions and in a rotary manner in all three axes with at least xc2x145xc2x0.
When using the X-ray detector, it is possible to use both an areal detector, such as an image intensifier or a flat panel detector (amorphous silicon detector), as well as a line detector. According to the invention, when using the line detector the drive in the X or Z-axis can be used for advancing the line detector for areal image generation.
The space requirement for an X-ray inspection device is a further important criterion. The characterized apparatus for performing the method only requires a limited amount of space and compared with conventional installations the space requirement is reduced by approximately 50%.
The invention provides a method for inspecting objects, for detecting defects or irregularities therein, using X-radiation, in which the object to be inspected is brought into different spatial positions and stays there during image detection, wherein the X-ray components, comprising an X-ray tube and an X-ray detector, are moved only in a translatory manner and the object is moved in a gimbal suspension in a rotary manner in at least one axis and at a maximum in three axes x, y and z.
The invention also provides an apparatus for performing an inspection of objects, comprising an X-ray tube positioned over an inspection object, which tube is fixed by means of a suspension to a rail and is capable of moving in a translatory manner; an X-ray detector under the inspection object which detector is fixed to a rail and is capable of moving in a translatory manner; wherein the inspection object is placed and fixed on one or more pallets, which are connected with gimbal frames for the rotation of the inspection object in all three axes x, y and z.
The invention further provides a method for inspecting an object, which comprises the steps of:
a) providing a device for inspecting an object, which device comprises:
i) a radiation protection cabin having an inside and an outside,
ii) at least one translatory movement unit attached to the inside of the radiation protection cabin, which translatory movement unit comprises one or more rails;
iii) one or more object support pallets within the radiation protection cabin, which support pallet or pallets are connected with gimbal frames, and which gimbal frames are attached to drives and are capable of moving or tilting the pallet or pallets;
iv) an X-ray tube fixed to a rail of the translatory movement unit, which X-ray tube is suspended above the pallet or pallets, and which X-ray tube is capable of moving in a translatory manner along the rail;
v) an X-ray detector fixed to a rail of the translatory movement unit, which X-ray detector is present under the pallet or pallets, and which X-ray detector is capable of moving in a translatory manner along the rail;
b) providing at least one test object, and placing the test object on the pallet or pallets such that the object is beneath the X-ray tube and above the X-ray detector; and
c) subjecting the test object to X-radiation in a plurality of spatial positions to thereby detect an image of the test object in each spatial position, wherein the X-ray tube and the X-ray detector are moved only in a translatory manner, and wherein the test object is moved in a gimbal suspension in a rotary manner in at least one axis and in a maximum of three axes x, y, and z.
The invention still further provides a device for inspecting an object, which device comprises:
i) a radiation protection cabin having an inside and an outside,
ii) at least one translatory movement unit attached to the inside of the radiation protection cabin, which translatory movement unit comprises one or more rails;
iii) one or more object support pallets within the radiation protection cabin, which support pallet or pallets are connected with gimbal frames, and which gimbal frames are attached to drives and are capable of moving or tilting the pallet or pallets;
iv) an X-ray tube fixed to a rail of the translatory movement unit, which X-ray tube is suspended above the pallet or pallets, and which X-ray tube is capable of moving in a translatory manner along the rail; and
v) an X-ray detector fixed to a rail of the translatory movement unit, which X-ray detector is present under the pallet or pallets, and which X-ray detector is capable of moving in a translatory manner along the rail.